Vacuum operated positive tooth clutches



March 8, 1955 R. K. SUPER VACUUM OPERATED POSITIVE TOOTH CLUTCHES Filed Sept. 27, 1948 2 Sheets-Sheet 1 Fig.

INVENTOR Ralph K. Super By 7 M7 Aflarne q March 8, 1955 R. K. SUPER 2,703,638

VACUUM OPERATED POSITIVE TOOTH CLUTCHES Filed Sept. 2'7, 1948 2 Sheets-Sheet 2 INVE/V TOR Ralph K. Super A! arnays United States Patent This invention relates to powe has for; it's general ohj'et' ah'd *p conipact 'a'ii'd eflicintlyhpe designed f'or use in dnfiii'tidfi with heavy duty co" cia'l and 'ilitary ti'ifc'ls for "transmitting 'isbwer p que at sele'c'tiv'e "speeds aiijd dividing the p'plication thereof between tidal dfive aidesfhtthe i'rehi 1e.

-A more "particularbhfedtof rition resides in the provision of"'a"pbw'i t'forq d ofthfe abov'eiype comprising an input shaft--f6'r'conne" 'lonthe soiiifce of power and differential drive riifg, -t'"geth'r' with spaced axle drive shafts each hav hi'gh 1111 eed gears'rotatably'mo'ufnted therebnaiid-ho'r'l fii tahle shiftable clutch "ni'rrih'fl's oil to elec connect-said ge'arsindriv'ii'ig l 1 tlireyvith, vacuum tiperatedrhe'ahs fo simultaneously shifting -"s"aid clutch members "in op osite "directions intq I and 511i "df clutched engagement with the "respective hi h "and 10w speed drive "gears.

A'n additional object ofthe-invention'isto provide a simply "constructed actuator unit for the clutch I sfhifti'rfg means whereby the slidable "clutch "ineinb'er is disengaged from one 'gear =by'the power thrust 'of the actnator piston and shifted into clutched "engagement with the 'othe'r gear under "diminished p'ressure "by i the 'a'c-tion of "an '-in dependently operating spring.

- A further object of the invent-ion to provide *sim'pIe and efiective means --for :ipositively -l-imiting *the shifting movements of the clutch member in each direction to assure an accurately centered relationship of the lutch teethon said member with the clutch teeth on the shaft v n ears.

The present'inven "on further provides a simple indepn'diitlyoprable ineans'for locking'the diifere'n' e ingo'u't 6f ction 'a't'thebptionofthe 'dri'ver so 'at' powertorque'inay he difiefntially' applied twoveh axles,"or 'ln'ay lie equally div'ided hetwe'en aides.

Withthe abo've aridbthroficts in view,='the in\fenfiion residesi'n theirnproved power 'torqiie' divider an'd i'n' the form construction and-relative arrangement ofthe'several parts, as will here-inafter he -more-tully-des'crioed, illustrated in the aecompanyingdrawings and subsequently incorporated-in the subjoined claims,

In the drawings, wherein I have disclosed one simple and practical em odiment of the invention and in which similar refer e'rice hammers designate-corresponding; parts tlif'oughout 'the 'sevefal'views A M Figure 1 is a side elevationilll'i'st'rating' apower'td'rque dividing nnit'cdr'istriijctdin 'accordanee' with hire einbo'db merit 'of thedfive'ntion.

Figure -2'is a"'horizo'rital"seetional view *takhsubstantially on the l-ine='of"Figure '1, and

Figure 3' is a detail-verfiical sectiontale'n Substantially o'n the' line 3-3 of Figure 2.

Referring in further detail to -the-"drawings=- and more particularly ,to Figure 2 thereof, the vpower inputwshafl 10 is journalled at its opposite ends insuitablebearings 12, mounted in the fr'ont and rear'side'walls of thetrans fer case or gear housing 14,, The usual driving connections are provid d between the engi er in'qtor and -the fotw'ard end ofs haft 1'0, With er without a conventional change speed t'ra 2,703,638 Patented Mar. 8, 1955 e'iat ivl'y ebn'n'eeted by the usual ropeller shafts with the spaced rear axles of the vehicle; 7

A diiferen'tial drive assembly is carried by .input shaft 10 anfd includes the spaced le'fner'its 24 and 26 respective'l'y rofaftahly rhouii'ted on said shaft and provided on l v v J t'ine'sh with the ,pinio'ns '28 carri ea'by the arms of a spider 30 -ho'r'i-reitatztljly splin'e'dfto the shaft '10. Thus the elements 24 arld'26inay be differentially driven from the input shaft.

Theflifie'r'e'ritial gear elements 24 and 26 are provided with identical lowsp'ee'dd'rive 'gea'rs 32 'ancl34 respectively and also with identical high speed drive gears 36 and ss'respe'etive'ly. v

Spaced "gears 40 and 42 "are rtitatably 'i'nounted o'n the output shaft 16 and p'r'hvidedo'n their opposed'ends with 11144-511645 r spectively. The gear *Insimilarinaiin'er, spaced 'g'e'a'rsfls and 50am rotaeibly mounted on the 'ontpu't shaft 18 and provided on their opposed ends with internal clutchteeth "52 an6 5'4 respectivelyg g'earj'fltib'eiiig inco'nstarlt rhes'hwith'tli'e lows'peed drive gear 32 611 difier'e'ntial 'geai lerneiit 24, while gear e'ntial g'legar "element 26.

"P01" 6 piirpose'of lcfckili'g out' tlle differential action, the outer end of gear element 24 is provided'withexternal clutch teeth 56 aridhdj'ac'eiit thito and exrernally'toethed memberSB is keyed in "the 'inp'ut s'haft '10. An axially shift'abl'ednternally toothed collar 60 is 'slidabl'y engaged with the *teeth fof niernber "58 and "is actuated by the 'shifteflfor k' 62 (Fig. -1') "suitably mounted in housing "14 and -csp'erdted by suitable 'inqti'qn transmittin connections fro'rn 'the dr'ive'rs "cab of the vehicle. when "the collar 60*'is-shifted' to the position shown in 'Figu're 2 to engage its internal teeth with teeth 56 on thedifierential gear el'em ent 24, "said "element, "the spider 3'0 and gear element 26 "together with member 58 'will then rotate as a unit with the-"ihpufshaft 10' so"that"theehgine power tor'que will "be equally -1iivide'd between "the "outp'l'ltshafts 16 and 18 audthc two 'rear'a'xles ofthe 'vehicle. This :is' desirahle when driving in the low spe'edgear ratio under-adverse'road "conditions.

'Between the I spaced gears o'n output shafts I6 and 18 clutch members "64 and "66 respectively are splined on said 'shafts so that each clutch member "is axially slidable ou its *as'sociatedshaft but hon=rotatablewithrespect thereto. Ea-e11" of these clutch members isprovided at its opposite "ends with e'xternal clutch teeth for en'ga'g'emerit with the internal teeth on the opp'o'sed ends of the rotatable g'earswh' the Y output sha'tt. The clutch me'in'ber's are actuated by'shiftertorks '68 and '70 respectivelysuiv ablysecured tb thesh itterrods 72 and 74 moufite'd in the opposite side walls' of housing 14 for axial 'rn'ovemerit.

Preferably 1 1 provide vacuum "controlled ac'ituators 'assoc'iated With-theshifter rods 72 and 74"for'sirnultaneously shiftingthe cli'ltch rriembei's fi-l and 66 in oppositedire'ctiofis into a'nd out of effective engagement withthespaced gar's *on "the respective 1 power output shafts. As these actu-ators aTe of=idei1ticalconstruct-ion, the following description of'fhe one "associated with shifter 'rod '72, as sh'o'wn irl' Figure 2- of the d'rawifig; will suflice for a 'clear' understanding of th'eiroperation,

---Inco-axial relation Withthe frontend of shifter rod 72, projecting torwardlytrom the frontwalbefI hohsi-ng 1'4, an -her-metically sealed casing 76 is rigidlylseeured to the housing wall. A suitable sealing unit 78 surrounds the rod-7-2 and prevents-thezleakageof: lubr-icant fromthe interior -of--housing 14, into the casing -76. Within the casing; 76, -a.-piston80 is-periphera 1ly-connected with .the cylindrical easing wall by a flexible membrane or '\-dia-- phram -82. v

The end of -shitter rod 72 -is-prov-ided with an" axially extending bore' 84 -having a; shoulder -86 spaced. from-the innerend thereof A- centrally aper-tured disc.83 is seated on-shoulde r--86. -A=sleeve 89 isfslidablyfitted withiuit-he to the piston 80 and is movable through the apertured disc 88 against the resistance of coil spring 92 surrounding said piston rod and bearing at one end against the disc 88 and at its other end against a disc 94 in abutting contact with shoulder 96 formed by the enlarged diameter outer end portion of the piston rod. Travel of sliable sleeve 89 in opposite directions is limited by abutment with discs 88 and 94. Outward movement of the disc 94 from the bore of the rod 72 is prevented by a split resilient ring 98 seated in an internal groove in the wall of said bore. Outward movement of the piston rod 90 through the disc 88 is limited by nut 100 threaded on I the inner end of the piston rod.

At its opposite end, the shifter rod 72 is formed with an elongated recess providing longitudinally spaced stop shoulders 102 and 104 respectively. These shoulders are adapted to contact opposite side of a stop disc 106 secured to the outer face of the rear side wall of housing 14, together with a hollow cap member 108 which receives the end of the shifter rod 72, by means of the bolts 110. The opening in disc 106 through which the rod 72 moves is of the required form to provide the part 112 on said disc located in the recess and with which the shoulders 102 and 104 abut. The position of disc 106 with respect to the stop shoulders is properly adjusted by interposing one or more shim plates 114 between said disc and the wall of gear housing 14.

The casings 76 of the two actuator units are internally connected at opposite sides of the piston 80 with the engine manifold or other source of vacuum. For this purpose I have diagramatically illustrated in Figure 2 of the drawings a suitable type of control valve 116 and connecting conduits 120 between said valve and the actuator casings 76 at opposite sides of the pistons therein. The valve 116 is properly operated from the drivers cab by suitable connections indicated at 118 to selectively establish communication between the source of vacuum and the actuators through the conduits 120 at relatively opposite sides of their respective pistons 80 whereby the clutch members 64 and 66 are axially shifted in relatively opposite directions on the respective output shafts 16 and 18.

As shown in Figure 2 of the drawings the clutch members are engaged with the gears 42 and 48 to transmit driving torque from the input shaft 10 through the differential gearing to the respective output shafts 16 and 18 at the low speed ratio. When it is desired to establish the high speed driving ratio, the position of valve 116 is reversed and the source of vacuum connected with the actuator for shift rod 72 at the left hand side of its piston 80 and at the right hand side of the actuator piston for shift rod 74. Thus the piston associated with rod 72 would be moved toward the left and in the initial portion of this movement spring 92 is compressed between disc 94 and disc 88 which is seated on shoulder 86 as the piston rod moves axially relative to rod 72. At the same time, the driving torque on gear 42 is released and in the continued movement of the piston 80, the disc 94 abutting the end of sleeve 89 moves rod 72 to the left, and thereby positively shifts the clutch member 64 under high pressure out of engagement with the clutch teeth 46 on gear 42. Thereupon, spring 92 expands to continue the movement of rod 72 and yieldingly urge clutch member 64 into contact with the clutch teeth on the high speed gear 40 and, upon synchronization, effects a full meshed engagement of the teeth on member 64 with the teeth 44 on said gear. This final shifting movement of the clutch member under the action of spring 92 is definitely limited by contact of stop shoulder 104 on rod 72 with the disc 106 to assure accurate alignment and the most effective torque transmitting relationship between the teeth on the clutch member and the teeth on the gear 40.

The same shifting operation of the clutch member 66 in the opposite direction simultaneously occurs and as the actuator piston 80 therefor moves to the right, sleeve 89 is first axially moved relative to rod 74 to compress spring 92 and upon contact of the end of sleeve 89 with disc 94, rod 74 is positively moved to the right to disengage clutch member 66 from the teeth on gear 48, whereupon as spring 92 expands, the movement of said clutch member is continued toward the right and engaged with the clutch teeth on gear 50 in the manner above explained, such engaged position being definitely limited by contact of stop shoulder 102 on rod 74 with disc 106.

From the foregoing description and the accompanying 1 collar and operably drawings, it will be seen that the improved vacuum operated clutch shifting devices insures the quick and accurate shifting movement of the clutch members between selective driving positions, while avoiding metallic clash, excessive torque stresses and possible damage to the parts which might result from partial clutch tooth engagement. While the full power stroke of the actuator pistons is employed to disengage the teeth of the shiftable clutch members from the teeth on the gear elements, the movement of said clutch members to their engaged positions with the teeth on the gear elements is effected by yielding spring pressure and independently of the power movement of the actuator piston. The adjustable stop means 106 for assuring a fully intermeshed relationship of the teeth on the clutch member and gear element and the most effective transmission of the driving torque to the power output shaft is also an important practical feature of the invention.

The invention may be embodied in other specific forms without departing from the spirit and essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In combination, a variable speed power apparatus having a support on which a speed selector element is reciprocated between two axially spaced positions, a rod reciprocable on said support parallel to the path of said element, a fluid powered device connected to one end of said rod for reciprocating the rod between said positions, a recess in the other end of said rod providing longitudinally spaced shoulders thereon, and a relatively stationary stop plate removably mounted on said support projecting into said recess between said shoulders so that opposite sides of said stop plate are abutted by one or the other of said shoulders when the rod is moved by said device to shift said element into either position.

2. In the combination defined in claim 1, said stop plate mounted on the support being apertured to slidably pass said rod and having a projection extending into said recess for contact by said shoulders.

3. In combination, a variable speed power transmission having a housing, a clutch collar within said housing slidable between two different drive speed ratio positions comprising a power operated rod slidably mounted in said housing parallel to the direction of shift of said connected to said collar. a fluid pressure differential responsive device connected to one end of said rod at one side of said housing, and means arresting longitudinal movement of said rod when said collar reaches either of said positions comprising a surface recess in said rod providing longitudinally spaced stop shoulders, a cap secured to said housing over said other end of said rod and a plate secured between said cap and said housing having an aperture to permit passage of said rod and a projection extending into said recess to engage one of said shoulders when the rod has moved to one or the other of said positions.

4. In combination, a variable speed power apparatus having a support on which a speed selector element is reciprocated between two axially spaced positions, a rod reciprocable on said support parallel to the path of said element, a fluid powered device connected to one end of said rod for reciprocating the rod between said positions, a recess in the other end of said rod providing longitudinally spaced shoulders thereon, a relatively stationary stop member on said support comprising a plate removably secured to said support and projecting into said recess between said shoulders so that said plate is abutted by one of said shoulders when the rod is moved by said device to shift said element into either position, and a plurality of shims between the plate and support for determining the relative disposition of the plate in the recess, said shims constituting an adjustment for said plate.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Williams Apr. 26, 1892 Bearbalck June 8, 1909 Kleinhan June 21, 1910 McAllister Mar. 21, 1933 Penati Mar. 5, 1935 Kelley Sept. 7, 1937 Fawick Nov. 30, 1937 Peal-main May 17, 1938 Buckendale Aug. 5, 1952 

